Short-range ensemble forecasts from the Met Office and GFS models indicate a daytime maximum near 19–20 °C for Warsaw on August 18, driven by westerly flow, increased cloud cover, and scattered showers that limit insolation and boundary-layer warming. This positions the closely matched leading market outcomes at 20 °C (38.5 %) and 19 °C (34.5 %) as reflections of minor differences in timing and intensity of precipitation. Historical August maxima average 23 °C, so the current pattern represents a modest cool anomaly relative to climatology. Key variables include the exact degree of cloud suppression and any late-day clearing that could allow brief warming toward 21 °C. Updated model runs and afternoon observations over the next 48 hours will narrow the range before resolution.